1. Carbonate Chemistry in the Ocean

2. CO2 + H2O  H2CO3 (carbonic acid)
H2CO3  H+ + HCO3- (bicarbonate)
HCO3-  H+ + CO32- (carbonate)
Ca2+ + CO32-  CaCO3 (calcium carbonate – used by all shelled marine animals and diatoms)

4. Carbon Cycle Processes
Movement in atmosphere: atmospheric C as CO2 (0.04% of troposphere)
Primary production: photosynthesis (“carbon fixation”) moves C from atmosphere to organic molecules in organisms
Movement through food web: C moves in organic form from organism to organism
Aerobic respiration: organic molecules broken down to release CO2 back to atmosphere
Combustion: organic molecules broken by burning release CO2 back to atmosphere
Dissolving in oceans: C forms carbonate (CO32–) & bicarbonate (HCO3–)
Movement to sediments: C enters sediments, primarily as calcium carbonate (CaCO3)

5. The Carbon Cycle How are humans affecting the carbon cycle?
Which parts of the carbon cycle are considered short-term and which are considered long-term?